This invention relates to sheet metal building construction, and is more particularly directed to a roof support system employing sheet metal rafters, purlins, truss members, and the like.
Various approaches have been taken in the fabrication of buildings from sheet metal, and one typical approach is to employ single pieces of sheet metal for the roof structure. Such roof systems are discussed in U.S. Pat. Nos. 3,952,461 and 2,272,910. Rafters and purlins fabricated of sheet metal and suitable for use in supporting the roof of a structure are discussed in U.S. Pat. No. 4,192,119. A metal roof system is discussed in U.S. Pat. No. 4,389,829, and in that system metal rafters, purlins, and trusses are joined with a spring metal truss pin or clip. However, that truss pin requires the truss member to have a bent-over end portion that must be aligned with the rafter or purlin with which it is to be connected. Bending and forming tools are required to form and assemble the trusses onto the rafters or purlins.